/******************************************************
The low-level file system

(c) 1995 Innobase Oy

Created 10/25/1995 Heikki Tuuri
*******************************************************/

#ifndef fil0fil_h
#define fil0fil_h

#include "univ.i"
#include "sync0rw.h"
#include "dict0types.h"
#include "ibuf0types.h"
#include "ut0byte.h"
#include "os0file.h"

/* When mysqld is run, the default directory "." is the mysqld datadir, but in
ibbackup we must set it explicitly; the patgh must NOT contain the trailing
'/' or '\' */
extern const char *fil_path_to_mysql_datadir;

/* Initial size of a single-table tablespace in pages */
#define FIL_IBD_FILE_INITIAL_SIZE 4

/* 'null' (undefined) page offset in the context of file spaces */
#define FIL_NULL ULINT32_UNDEFINED

/* Space address data type; this is intended to be used when
addresses accurate to a byte are stored in file pages. If the page part
of the address is FIL_NULL, the address is considered undefined. */

typedef byte fil_faddr_t; /* 'type' definition in C: an address
                          stored in a file page is a string of bytes */
#define FIL_ADDR_PAGE 0   /* first in address is the page offset */
#define FIL_ADDR_BYTE 4   /* then comes 2-byte byte offset within page*/

#define FIL_ADDR_SIZE 6 /* address size is 6 bytes */

/* A struct for storing a space address FIL_ADDR, when it is used
in C program data structures. */

typedef struct fil_addr_struct fil_addr_t;
struct fil_addr_struct
{
  ulint page;    /* page number within a space */
  ulint boffset; /* byte offset within the page */
};

/* Null file address */
extern fil_addr_t fil_addr_null;

/* The byte offsets on a file page for various variables */
#define FIL_PAGE_SPACE_OR_CHKSUM                              \
  0                       /* in < MySQL-4.0.14 space id the   \
                          page belongs to (== 0) but in later \
                          versions the 'new' checksum of the  \
                          page */
#define FIL_PAGE_OFFSET 4 /* page offset inside space */
#define FIL_PAGE_PREV                      \
  8 /* if there is a 'natural' predecessor \
    of the page, its offset */
#define FIL_PAGE_NEXT                     \
  12 /* if there is a 'natural' successor \
     of the page, its offset */
#define FIL_PAGE_LSN                 \
  16 /* lsn of the end of the newest \
     modification log record to the page */
#define FIL_PAGE_TYPE                       \
  24 /* file page type: FIL_PAGE_INDEX,..., \
     2 bytes */
#define FIL_PAGE_FILE_FLUSH_LSN           \
  26 /* this is only defined for the      \
     first page in a data file: the file  \
     has been flushed to disk at least up \
     to this lsn */
#define FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID             \
  34                     /* starting from 4.1.x this \
                    contains the space id of the page */
#define FIL_PAGE_DATA 38 /* start of the data on the page */

/* File page trailer */
#define FIL_PAGE_END_LSN_OLD_CHKSUM     \
  8 /* the low 4 bytes of this are used \
    to store the page checksum, the     \
    last 4 bytes should be identical    \
    to the last 4 bytes of FIL_PAGE_LSN */
#define FIL_PAGE_DATA_END 8

/* File page types */
#define FIL_PAGE_INDEX 17855
#define FIL_PAGE_UNDO_LOG 2
#define FIL_PAGE_INODE 3
#define FIL_PAGE_IBUF_FREE_LIST 4

/* Space types */
#define FIL_TABLESPACE 501
#define FIL_LOG 502

extern ulint fil_n_log_flushes;

extern ulint fil_n_pending_log_flushes;
extern ulint fil_n_pending_tablespace_flushes;

/***********************************************************************
Returns the version number of a tablespace, -1 if not found. */

ib_longlong fil_space_get_version(
    /*==================*/
    /* out: version number, -1 if the tablespace does not
    exist in the memory cache */
    ulint id); /* in: space id */
/***********************************************************************
Returns the latch of a file space. */

rw_lock_t *fil_space_get_latch(
    /*================*/
    /* out: latch protecting storage allocation */
    ulint id); /* in: space id */
/***********************************************************************
Returns the type of a file space. */

ulint fil_space_get_type(
    /*===============*/
    /* out: FIL_TABLESPACE or FIL_LOG */
    ulint id); /* in: space id */
/***********************************************************************
Returns the ibuf data of a file space. */

ibuf_data_t *fil_space_get_ibuf_data(
    /*====================*/
    /* out: ibuf data for this space */
    ulint id); /* in: space id */
/***********************************************************************
Appends a new file to the chain of files of a space. File must be closed. */

void fil_node_create(
    /*============*/
    const char *name, /* in: file name (file must be closed) */
    ulint size,       /* in: file size in database blocks, rounded
                      downwards to an integer */
    ulint id,         /* in: space id where to append */
    ibool is_raw);    /* in: TRUE if a raw device or
                      a raw disk partition */
/********************************************************************
Drops files from the start of a file space, so that its size is cut by
the amount given. */

void fil_space_truncate_start(
    /*=====================*/
    ulint id,         /* in: space id */
    ulint trunc_len); /* in: truncate by this much; it is an error
                      if this does not equal to the combined size of
                      some initial files in the space */
/***********************************************************************
Creates a space memory object and puts it to the 'fil system' hash table. If
there is an error, prints an error message to the .err log. */

ibool fil_space_create(
    /*=============*/
    /* out: TRUE if success */
    const char *name, /* in: space name */
    ulint id,         /* in: space id */
    ulint purpose);   /* in: FIL_TABLESPACE, or FIL_LOG if log */
/***********************************************************************
Frees a space object from a the tablespace memory cache. Closes the files in
the chain but does not delete them. */

ibool fil_space_free(
    /*===========*/
    /* out: TRUE if success */
    ulint id); /* in: space id */
/***********************************************************************
Returns the size of the space in pages. The tablespace must be cached in the
memory cache. */

ulint fil_space_get_size(
    /*===============*/
    /* out: space size, 0 if space not found */
    ulint id); /* in: space id */
/***********************************************************************
Checks if the pair space, page_no refers to an existing page in a tablespace
file space. The tablespace must be cached in the memory cache. */

ibool fil_check_adress_in_tablespace(
    /*===========================*/
    /* out: TRUE if the address is meaningful */
    ulint id,       /* in: space id */
    ulint page_no); /* in: page number */
/********************************************************************
Initializes the tablespace memory cache. */

void fil_init(
    /*=====*/
    ulint max_n_open); /* in: max number of open files */
/***********************************************************************
Opens all log files and system tablespace data files. They stay open until the
database server shutdown. This should be called at a server startup after the
space objects for the log and the system tablespace have been created. The
purpose of this operation is to make sure we never run out of file descriptors
if we need to read from the insert buffer or to write to the log. */

void fil_open_log_and_system_tablespace_files(void);
/*==========================================*/
/***********************************************************************
Closes all open files. There must not be any pending i/o's or not flushed
modifications in the files. */

void fil_close_all_files(void);
/*=====================*/
/***********************************************************************
Sets the max tablespace id counter if the given number is bigger than the
previous value. */

void fil_set_max_space_id_if_bigger(
    /*===========================*/
    ulint max_id); /* in: maximum known id */
/********************************************************************
Initializes the ibuf data structure for space 0 == the system tablespace.
This can be called after the file space headers have been created and the
dictionary system has been initialized. */

void fil_ibuf_init_at_db_start(void);
/*===========================*/
/********************************************************************
Writes the flushed lsn and the latest archived log number to the page
header of the first page of each data file in the system tablespace. */

ulint fil_write_flushed_lsn_to_data_files(
    /*================================*/
    /* out: DB_SUCCESS or error number */
    dulint lsn,         /* in: lsn to write */
    ulint arch_log_no); /* in: latest archived log file number */
/***********************************************************************
Reads the flushed lsn and arch no fields from a data file at database
startup. */

void fil_read_flushed_lsn_and_arch_log_no(
    /*=================================*/
    os_file_t data_file,    /* in: open data file */
    ibool one_read_already, /* in: TRUE if min and max parameters
                            below already contain sensible data */
#ifdef UNIV_LOG_ARCHIVE
    ulint *min_arch_log_no,   /* in/out: */
    ulint *max_arch_log_no,   /* in/out: */
#endif                        /* UNIV_LOG_ARCHIVE */
    dulint *min_flushed_lsn,  /* in/out: */
    dulint *max_flushed_lsn); /* in/out: */
/***********************************************************************
Increments the count of pending insert buffer page merges, if space is not
being deleted. */

ibool fil_inc_pending_ibuf_merges(
    /*========================*/
    /* out: TRUE if being deleted, and ibuf merges should
    be skipped */
    ulint id); /* in: space id */
/***********************************************************************
Decrements the count of pending insert buffer page merges. */

void fil_decr_pending_ibuf_merges(
    /*========================*/
    ulint id); /* in: space id */
/***********************************************************************
Parses the body of a log record written about an .ibd file operation. That is,
the log record part after the standard (type, space id, page no) header of the
log record.

If desired, also replays the delete or rename operation if the .ibd file
exists and the space id in it matches. Replays the create operation if a file
at that path does not exist yet. If the database directory for the file to be
created does not exist, then we create the directory, too.

Note that ibbackup --apply-log sets fil_path_to_mysql_datadir to point to the
datadir that we should use in replaying the file operations. */

byte *fil_op_log_parse_or_replay(
    /*=======================*/
    /* out: end of log record, or NULL if the
    record was not completely contained between
    ptr and end_ptr */
    byte *ptr,       /* in: buffer containing the log record body,
                     or an initial segment of it, if the record does
                     not fir completely between ptr and end_ptr */
    byte *end_ptr,   /* in: buffer end */
    ulint type,      /* in: the type of this log record */
    ibool do_replay, /* in: TRUE if we want to replay the
                     operation, and not just parse the log record */
    ulint space_id); /* in: if do_replay is TRUE, the space id of
                     the tablespace in question; otherwise
                     ignored */
/***********************************************************************
Deletes a single-table tablespace. The tablespace must be cached in the
memory cache. */

ibool fil_delete_tablespace(
    /*==================*/
    /* out: TRUE if success */
    ulint id); /* in: space id */
/***********************************************************************
Discards a single-table tablespace. The tablespace must be cached in the
memory cache. Discarding is like deleting a tablespace, but
1) we do not drop the table from the data dictionary;
2) we remove all insert buffer entries for the tablespace immediately; in DROP
TABLE they are only removed gradually in the background;
3) when the user does IMPORT TABLESPACE, the tablespace will have the same id
as it originally had. */

ibool fil_discard_tablespace(
    /*===================*/
    /* out: TRUE if success */
    ulint id); /* in: space id */
/***********************************************************************
Renames a single-table tablespace. The tablespace must be cached in the
tablespace memory cache. */

ibool fil_rename_tablespace(
    /*==================*/
    /* out: TRUE if success */
    const char *old_name,  /* in: old table name in the standard
                           databasename/tablename format of
                           InnoDB, or NULL if we do the rename
                           based on the space id only */
    ulint id,              /* in: space id */
    const char *new_name); /* in: new table name in the standard
                           databasename/tablename format
                           of InnoDB */

/***********************************************************************
Creates a new single-table tablespace to a database directory of MySQL.
Database directories are under the 'datadir' of MySQL. The datadir is the
directory of a running mysqld program. We can refer to it by simply the
path '.'. Tables created with CREATE TEMPORARY TABLE we place in the temp
dir of the mysqld server. */

ulint fil_create_new_single_table_tablespace(
    /*===================================*/
    /* out: DB_SUCCESS or error code */
    ulint *space_id,       /* in/out: space id; if this is != 0,
                           then this is an input parameter,
                           otherwise output */
    const char *tablename, /* in: the table name in the usual
                           databasename/tablename format
                           of InnoDB, or a dir path to a temp
                           table */
    ibool is_temp,         /* in: TRUE if a table created with
                           CREATE TEMPORARY TABLE */
    ulint size);           /* in: the initial size of the
                           tablespace file in pages,
                           must be >= FIL_IBD_FILE_INITIAL_SIZE */
/************************************************************************
Tries to open a single-table tablespace and optionally checks the space id is
right in it. If does not succeed, prints an error message to the .err log. This
function is used to open a tablespace when we start up mysqld, and also in
IMPORT TABLESPACE.
NOTE that we assume this operation is used either at the database startup
or under the protection of the dictionary mutex, so that two users cannot
race here. This operation does not leave the file associated with the
tablespace open, but closes it after we have looked at the space id in it. */

ibool fil_open_single_table_tablespace(
    /*=============================*/
    /* out: TRUE if success */
    ibool check_space_id, /* in: should we check that the space
                          id in the file is right; we assume
                          that this function runs much faster
                          if no check is made, since accessing
                          the file inode probably is much
                          faster (the OS caches them) than
                          accessing the first page of the file */
    ulint id,             /* in: space id */
    const char *name);    /* in: table name in the
                          databasename/tablename format */
/************************************************************************
It is possible, though very improbable, that the lsn's in the tablespace to be
imported have risen above the current system lsn, if a lengthy purge, ibuf
merge, or rollback was performed on a backup taken with ibbackup. If that is
the case, reset page lsn's in the file. We assume that mysqld was shut down
after it performed these cleanup operations on the .ibd file, so that it at
the shutdown stamped the latest lsn to the FIL_PAGE_FILE_FLUSH_LSN in the
first page of the .ibd file, and we can determine whether we need to reset the
lsn's just by looking at that flush lsn. */

ibool fil_reset_too_high_lsns(
    /*====================*/
    /* out: TRUE if success */
    const char *name,    /* in: table name in the
                         databasename/tablename format */
    dulint current_lsn); /* in: reset lsn's if the lsn stamped
                         to FIL_PAGE_FILE_FLUSH_LSN in the
                         first page is too high */
/************************************************************************
At the server startup, if we need crash recovery, scans the database
directories under the MySQL datadir, looking for .ibd files. Those files are
single-table tablespaces. We need to know the space id in each of them so that
we know into which file we should look to check the contents of a page stored
in the doublewrite buffer, also to know where to apply log records where the
space id is != 0. */

ulint fil_load_single_table_tablespaces(void);
/*===================================*/
/* out: DB_SUCCESS or error number */
/************************************************************************
If we need crash recovery, and we have called
fil_load_single_table_tablespaces() and dict_load_single_table_tablespaces(),
we can call this function to print an error message of orphaned .ibd files
for which there is not a data dictionary entry with a matching table name
and space id. */

void fil_print_orphaned_tablespaces(void);
/*================================*/
/***********************************************************************
Returns TRUE if a single-table tablespace does not exist in the memory cache,
or is being deleted there. */

ibool fil_tablespace_deleted_or_being_deleted_in_mem(
    /*===========================================*/
    /* out: TRUE if does not exist or is being\
    deleted */
    ulint id,             /* in: space id */
    ib_longlong version); /* in: tablespace_version should be this; if
                         you pass -1 as the value of this, then this
                         parameter is ignored */
/***********************************************************************
Returns TRUE if a single-table tablespace exists in the memory cache. */

ibool fil_tablespace_exists_in_mem(
    /*=========================*/
    /* out: TRUE if exists */
    ulint id); /* in: space id */
/***********************************************************************
Returns TRUE if a matching tablespace exists in the InnoDB tablespace memory
cache. Note that if we have not done a crash recovery at the database startup,
there may be many tablespaces which are not yet in the memory cache. */

ibool fil_space_for_table_exists_in_mem(
    /*==============================*/
    /* out: TRUE if a matching tablespace
    exists in the memory cache */
    ulint id,         /* in: space id */
    const char *name, /* in: table name in the standard
                      'databasename/tablename' format or
                      the dir path to a temp table */
    ibool is_temp,    /* in: TRUE if created with CREATE
                      TEMPORARY TABLE */
    ibool mark_space, /* in: in crash recovery, at database
                      startup we mark all spaces which have
                      an associated table in the InnoDB
                      data dictionary, so that
                      we can print a warning about orphaned
                      tablespaces */
    ibool print_error_if_does_not_exist);
/* in: print detailed error
information to the .err log if a
matching tablespace is not found from
memory */
/**************************************************************************
Tries to extend a data file so that it would accommodate the number of pages
given. The tablespace must be cached in the memory cache. If the space is big
enough already, does nothing. */

ibool fil_extend_space_to_desired_size(
    /*=============================*/
    /* out: TRUE if success */
    ulint *actual_size,       /* out: size of the space after extension;
                              if we ran out of disk space this may be lower
                              than the desired size */
    ulint space_id,           /* in: space id */
    ulint size_after_extend); /* in: desired size in pages after the
                           extension; if the current space size is bigger
                           than this already, the function does nothing */
#ifdef UNIV_HOTBACKUP
/************************************************************************
Extends all tablespaces to the size stored in the space header. During the
ibbackup --apply-log phase we extended the spaces on-demand so that log records
could be appllied, but that may have left spaces still too small compared to
the size stored in the space header. */

void fil_extend_tablespaces_to_stored_len(void);
/*======================================*/
#endif
/***********************************************************************
Tries to reserve free extents in a file space. */

ibool fil_space_reserve_free_extents(
    /*===========================*/
    /* out: TRUE if succeed */
    ulint id,            /* in: space id */
    ulint n_free_now,    /* in: number of free extents now */
    ulint n_to_reserve); /* in: how many one wants to reserve */
/***********************************************************************
Releases free extents in a file space. */

void fil_space_release_free_extents(
    /*===========================*/
    ulint id,          /* in: space id */
    ulint n_reserved); /* in: how many one reserved */
/***********************************************************************
Gets the number of reserved extents. If the database is silent, this number
should be zero. */

ulint fil_space_get_n_reserved_extents(
    /*=============================*/
    ulint id); /* in: space id */
/************************************************************************
Reads or writes data. This operation is asynchronous (aio). */

ulint fil_io(
    /*===*/
    /* out: DB_SUCCESS, or DB_TABLESPACE_DELETED
    if we are trying to do i/o on a tablespace
    which does not exist */
    ulint type,         /* in: OS_FILE_READ or OS_FILE_WRITE,
                        ORed to OS_FILE_LOG, if a log i/o
                        and ORed to OS_AIO_SIMULATED_WAKE_LATER
                        if simulated aio and we want to post a
                        batch of i/os; NOTE that a simulated batch
                        may introduce hidden chances of deadlocks,
                        because i/os are not actually handled until
                        all have been posted: use with great
                        caution! */
    ibool sync,         /* in: TRUE if synchronous aio is desired */
    ulint space_id,     /* in: space id */
    ulint block_offset, /* in: offset in number of blocks */
    ulint byte_offset,  /* in: remainder of offset in bytes; in
                        aio this must be divisible by the OS block
                        size */
    ulint len,          /* in: how many bytes to read or write; this
                        must not cross a file boundary; in aio this
                        must be a block size multiple */
    void *buf,          /* in/out: buffer where to store read data
                        or from where to write; in aio this must be
                        appropriately aligned */
    void *message);     /* in: message for aio handler if non-sync
                        aio used, else ignored */
/************************************************************************
Reads data from a space to a buffer. Remember that the possible incomplete
blocks at the end of file are ignored: they are not taken into account when
calculating the byte offset within a space. */

ulint fil_read(
    /*=====*/
    /* out: DB_SUCCESS, or DB_TABLESPACE_DELETED
    if we are trying to do i/o on a tablespace
    which does not exist */
    ibool sync,         /* in: TRUE if synchronous aio is desired */
    ulint space_id,     /* in: space id */
    ulint block_offset, /* in: offset in number of blocks */
    ulint byte_offset,  /* in: remainder of offset in bytes; in aio
                        this must be divisible by the OS block size */
    ulint len,          /* in: how many bytes to read; this must not
                        cross a file boundary; in aio this must be a
                        block size multiple */
    void *buf,          /* in/out: buffer where to store data read;
                        in aio this must be appropriately aligned */
    void *message);     /* in: message for aio handler if non-sync
                        aio used, else ignored */
/************************************************************************
Writes data to a space from a buffer. Remember that the possible incomplete
blocks at the end of file are ignored: they are not taken into account when
calculating the byte offset within a space. */

ulint fil_write(
    /*======*/
    /* out: DB_SUCCESS, or DB_TABLESPACE_DELETED
    if we are trying to do i/o on a tablespace
    which does not exist */
    ibool sync,         /* in: TRUE if synchronous aio is desired */
    ulint space_id,     /* in: space id */
    ulint block_offset, /* in: offset in number of blocks */
    ulint byte_offset,  /* in: remainder of offset in bytes; in aio
                        this must be divisible by the OS block size */
    ulint len,          /* in: how many bytes to write; this must
                        not cross a file boundary; in aio this must
                        be a block size multiple */
    void *buf,          /* in: buffer from which to write; in aio
                        this must be appropriately aligned */
    void *message);     /* in: message for aio handler if non-sync
                        aio used, else ignored */
/**************************************************************************
Waits for an aio operation to complete. This function is used to write the
handler for completed requests. The aio array of pending requests is divided
into segments (see os0file.c for more info). The thread specifies which
segment it wants to wait for. */

void fil_aio_wait(
    /*=========*/
    ulint segment); /* in: the number of the segment in the aio
                    array to wait for */
/**************************************************************************
Flushes to disk possible writes cached by the OS. If the space does not exist
or is being dropped, does not do anything. */

void fil_flush(
    /*======*/
    ulint space_id); /* in: file space id (this can be a group of
                     log files or a tablespace of the database) */
/**************************************************************************
Flushes to disk writes in file spaces of the given type possibly cached by
the OS. */

void fil_flush_file_spaces(
    /*==================*/
    ulint purpose); /* in: FIL_TABLESPACE, FIL_LOG */
/**********************************************************************
Checks the consistency of the tablespace cache. */

ibool fil_validate(void);
/*==============*/
/* out: TRUE if ok */
/************************************************************************
Returns TRUE if file address is undefined. */

ibool fil_addr_is_null(
    /*=============*/
    /* out: TRUE if undefined */
    fil_addr_t addr); /* in: address */
/************************************************************************
Accessor functions for a file page */

ulint fil_page_get_prev(byte *page);
ulint fil_page_get_next(byte *page);
/*************************************************************************
Sets the file page type. */

void fil_page_set_type(
    /*==============*/
    byte *page,  /* in: file page */
    ulint type); /* in: type */
/*************************************************************************
Gets the file page type. */

ulint fil_page_get_type(
    /*==============*/
    /* out: type; NOTE that if the type has not been
    written to page, the return value not defined */
    byte *page); /* in: file page */

typedef struct fil_space_struct fil_space_t;

#endif
